Harley Benton PowerPlant ISO-5 Pro

I bought this specifically to drive two pedals each requiring 400mW isolated power and the ISO-5 is advertised as providing five isolated channels, two of them provide up to 500mW. Unfortunately, upon connecting everything, I get a lot of digital noise from the pedals. If I go back to two different power supplies, there is no problem.

So, it seems the isolation is not sufficient for modern digital pedals... perhaps it is better to invest in a power supply three times as expensive anyway!?!